What I have: MacOS 10.15.7 Catalina What I need: MacOS 10.16 Big Sur
I have: MacOS 10.15.7 Catalina. I need: MacOS 10.16 Big Sur
How do I install MacOS 10.16 Big Sur?
iMac 27″, macOS 10.15
Question marked as
If your Mac is on this list: macOS Big Sur is compatible with these computers - Apple Support then you can get the full Big Sur 11.7.5 installer from How to download macOS - Apple Support
I recommend that you verify with your printer/scanner vendor and third-party application providers that they have compatible drivers/applications for Big Sur — before you upgrade. Perform a last Time Machine backup on Catalina, and then park that drive. Start with a new Time Machine drive formatted as APFS for the first Big Sur full backup. I have had good results with Crucial X8 SSDs for TM drives across multiple Macs and operating systems.